I've heard some good things about Rails, but I don't know much about it yet. There are only a few questions about Rails on GIS.SE (and there's not even a Rails tag).
Is it worthwhile to learn about Rails, from a GIS professional's perspective? (eg, what advantages does Rails give when building a website containing GIS functionality, compared to not using Rails?)
Are there any examples of good GIS/mapping websites built on Rails?
(I don't have any specific requirements in mind yet - I just want to know whether to invest time in learning Rails.)